Apparatus for mixing concrete



Aug. 15, 1933.? w JAIQKS' 1,922,368

APPARATUS FOR MIXING CONCRETE Original Filed March 19, 1951 [nvenor )VZ'Z 72 Jl. Jaz'cks' Jam?" 7259 5,

UNITEDSTA j to Patented Aug. 15, 1933 i APPARATUS F on MIXING ooNonETE Wilson A. 'Jaicks, Chicago, Ill.

,Original application Ma. 523,709; Divided and 1931. Serial No. 541,327

rch 19, 1931, Serial No. this application June 1,

.2. Claims. Class 83-73 My invention relates to apparatus for mixing concrete, One object of myinvention is to increase the amountof concrete that can be mixed in a given time without increasing the number of men Working on the job. Another object of my invention is to so assemble 'a plurality of separate and normally independent concrete mixers in such a relation that with a minimum increase in labor, a relatively great increase in output may be obtained. Other objects will appear from time to time throughoutthe specification and claims. 7 r I This application is a division of myco application Ser. No. 523,709 filed -pending March 19, 1931, Patent No. 1,815,857, July 21,1931

My inventionis illustrated more or less diagrammatically in the accompanying drawing, wherein-- Figure 1 is a side elevation of-my invention;

Figure 2 is an end elevation with the skip in the raised position; and r Figure 3 is a diagrammatic top plan View.

Like parts are indicated by like characters throughout the specification and drawing.

1 For the purpose of illustration, I have shown my invention applied to two conventional concrete mixers tied together in a fixed and permae nentrelation whereby my invention may be carried out. Clearly different types of mixers might be used, or a special design of mixer might be worked out which would embody my invention. In general, it will be understood. that road com missions and the like, in connection with contracts for concrete roads, specify and adhere very rigidly to the time during which the concrete must be mixed before it goes on the road. For instance, in the State of Illinois, concrete must be mixed one minute. This means that if the mixer is entirely charged and is started up and come to speed, itmust be allowed to run one minute before any more concrete can be put on the road. Meanwhile the whole crew is waiting for the machine to work. The machines are relatively large and bulky as it is, and they ordinarily extend clear across the entire width of pavement being poured, andthe crew can do nothing else except operate the paving or mixing machine.

I have discovered that'if I take two of the conventional types of paving machines, arrange them in tandem, tie them rigidly together by pins or stringers so that their relation remains permanent, I can greatly increase the amount of yardage that can be mixed and poured. This is done by assembling, either at a measuring station removed from the mixer or in the skip of the mixer, a predetermined proper batch of cement, sand and gravel. Then this batch, is raised by the skip and discharged into themixing drum, Water being at that time added in theproper amountfor the final mix. This batch is thenmixed for a little more or a little less than half the timere uired. Then the contents of the mixing drum are discharged into the skip of the second. drum, the contents fiowing'ire'ely by gravity from the discharge of. the first drum to the skip of the second, which skip is held in place to receive the entire contents of the'first drum by the tying together of the supporting members of the two paving machines. As soon as, the entire contents of the first drum has been discharged into the skip of the second and brought to rest as a batch, that batch of partially mixed concrete is, by the skip raised and discharged into the second drumwhere, without the addition of any more material of it is mixed a suificient length of time such that when added to the time of mixing in the first drum will give the total mixing time required by, the contract r In one practical instance where this process had been carried out, I prefer to mix the charge in the first paver for 26 seconds and in the second paver for, 34 seconds, making a total mixing time of one 'minute.,This doesnot take into consideration the mixing effect ,resulting from the discharge of the batch from, the first mixenits flowing or falling bygravity to the skip 'of the second, its being arrested there violently as-it impinges upon the ski its being poured by the skip into the second mixer. It is well known that pouring and arresting material of a fluid character promotes mixing, and in fact test beams show that beams made from concrete mixed by my'process are stronger than beams mixed by the conventional method, thus indicating that the transfer from one mixer to the next one is additionally useful in promoting better mixing.

Experience shows that by my method I can turn out from 65 to 70 batches of one minute mix concreete per hour, as compared with a usual output of to batches of one minute mix, in a single paver. Experience also shows that this can be done by simply adding one operator to theregular crew, and thisaddition of one operator and one paver increases the daily concrete production more than forty percent. In view of the fact that road contracts are usually let on a time basis and that the season is short, it will be at once apparent that this very great any kind whatever,

increase in output, with a very slight increase in labor, is much more than enough to compensate for the increased machinery cost.

A indicates the sub-grade upon which a road is to be laid. A the forms on both sides of the road between which the concrete is to be poured. A the concrete which has already been deposited and is subsequently to be treated by means forming no part of my present invention, to bring it to proper grade and level and smooth it over and make the road. A are the tracks of an industrial railroad. A dump cars adapted to. travel along the track, each car preferably containing a premeasured batch of dry aggregate, measured out and fed to the car by the measuring means indicated diagrammatically at A The cars are moved from the measuring means to the mixing means by any suitable means not indicated, and it will be understood that these cars might'be used for conveying unmeasured aggregate materials which might be measured in' themixing zone if desired.

B is the first mixer which comprises a mixing drum B a supporting platform B carried preferably on a track laying supporting truck B B is an engine which may be used to operate the track laying truck to move the mixer along the ground and may also be used to rotate the drum. B is a skip adapted in one position to rest on the ground and receive materials from the industrial railroad; or materials fed to it in any desired way. B is a hoist controlled by the engine for raising the skip to a point above the drum and causing the contents thereof to flow, by gravity, into the mixing drum. It will be noted that this mixer is almost as wide as the road. There is no room for another mixer along side of it.

C is the second mixer. In detail it is the same as the first one and the indicating characters applied to it are equally applicable to this'as to the first mixer B. It will be noted, however, that there are no means for supplyingwater to the second mixer. The entire amount of water is fed to the mix as it goes into the first mixer. C is an unloading chute associated with the first mixer B. It will be noted that thisunloading chute is spotted over the skip of the second mixer so that material from the first mixer is discharged from the first mixer and falls freely, under the influence of gravity, into the skip of the second mixer, which skip may be manipulated, when filled with the partially mixed batch from the first mixer, to discharge this partially mixed batch into the second. C C are tie rods joining the trucks of the two mixers together so as to maintain them in fixed relation, and especially so as to insure that the skip of the second mixer will always be spotted beneath the discharge from the first and thereby wastage and spilling of material will not take place. C is a crane arm associated with the second mixer and the carriage C travels along it. The arm is free to swing back and forth in a horizontal plane above the road. A bucket C is supported on the carriage C This bucket is adapted. to be spotted beneath the discharge chute of the second mixer and to be then run out along the crane arm to drop its load in any suitable point on the road, thereby making it unnecessary to move the mixers for every batch that is mixed.

I claim:

l. A concrete mixer comprising two mixing drums, independent supporting and propelling means therefor, tie rods joining said propelling and supporting means and adapted to maintain the distance between the drums constant, a skip adapted to load aggregate into one drum, means for mixing water with the aggregate and means for operating the drum to mix concrete, a skip associated with the second drum at a point below the first, means for discharging material from the first drum and causing it to fall by gravity to and be arrested in the second skip, means, including said second skip, for charging the mixture from the first drum into the second, means for operating the second drum to mix the concrete, and means for discharging the mixed concrete therefrom.

2. A concrete mixer comprising a plurality of mixing drums, independent supporting and propelling means therefor, tie rods joining said propelling and supporting means and adapted to maintain the distance between the drums constant, a skip adapted to load aggregate into one drum, means for mixing water with the aggregate and means for operating the drum to mix concrete, a skip associated with one of said drums at a point below the first mentioned drum, means for discharging material from the first mentioned drum and causing it to fall by gravity and be arrested in said skip, means, including said skip for charging the mixture thus discharged from the first mentioned drum into the next drum and means for operating such second drum to mix the concrete, and means for discharging the concrete therefrom.

WILSON A. JAICKS. 

